EiR: Doping cubic boron nitride, an extreme material for power electronics and radiation detection

EiR：掺杂立方氮化硼，一种用于电力电子和辐射检测的极端材料

• 批准号: 1831954
• 负责人: Michael Spencer
• 金额: $ 98.27万
• 依托单位: Morgan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1831954&HistoricalAwards=false
• 关键词: EiR; Doping; cubic; boron; nitride

This project focuses on cubic boron nitride for extreme applications. Boron nitride is member of the family of semiconductors known as III-nitrides, which consist of nitrogen and a Group III element such as aluminum, gallium, and indium. This family of materials has realized the solid-state lighting industry and revolutionized microwave communications. Cubic boron nitride is an ultra-wide bandgap material, transparent to visible light and absorbing only in the deep ultraviolet. It could have a transformative impact on power electronics for electric vehicles, smart grids, and space technologies. Its exceptional hardness, high thermal conductivity and corrosion resistance could also allow this material to replace diamond in harsh environments. Studies of boron nitride will also contribute to fundamental knowledge of III-nitride semiconductors. The project is a collaboration between Howard and Morgan State University, two Historically Black Colleges (HBCUs). The project enables Morgan and Howard students to participate in a cutting edge technology with commercial implications. The project explicitly engages both graduate students and undergraduates in "hands on" research activities. The project will fund senior design projects at Morgan and Howard, where students will translate physical electronics discoveries into real systems. The project will encourage greater minority participation in graduate research programs at HBCUs. To realize the full potential of cubic boron nitride (c-BN), it is desirable to have both n-type and p-type conduction enabling bipolar devices as well as Complementary Metal Oxide Semiconductor (CMOS) logic. It has been demonstrated that shallow n-type (silicon doping), and p-type (beryllium doping) are possible, making c-BN a unique outlier among ultrawide bandgap materials (UWBGs). In this work, we investigate doping and compensation strategies to evaluate the promise of c-BN. In addition we measure physical properties of this material such as mobility and breakdown field as a function of defect morphology (updating historical data as necessary). The work involves both small (1 mm) commercial single-crystal c-BN samples, as well as large area thin films grown at Morgan State. All measurements will be interpreted by comparing with first-principles density functional theory (DFT) calculations that provide a true atomic physics-based understanding. One of the challenges of the work will be to produce polytypic pure material. In order to accomplish this during chemical vapor deposition (CVD), the less stable hexagonal boron nitride (h-BN) polymorph is etched or sputtered away allowing the production of the cubic phase. We will test 3 methods to do this: i) etching by H2, ii) use of fluorine-based precursors and iii) ion-beam assistance, on single-crystal HPHT diamond substrates. Surface preparation and post-annealing will be guided by DFT calculations. Compensation and doping by intrinsic point defects (e.g. vacancies) are likely to play a strong role in this UWBG material, and DFT will be a critical tool to understanding the origin of the doping, and electrical transport. Diodes and metal-semiconductor-metal structures will be used as test devices.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目的重点是用于极端应用的立方氮化硼。氮化硼是被称为III族氮化物的半导体家族的成员，其由氮和第III族元素如铝、镓和铟组成。这一系列材料实现了固态照明工业，并彻底改变了微波通信。立方氮化硼是一种超宽带隙材料，对可见光透明，仅吸收深紫外线。它可能对电动汽车、智能电网和空间技术的电力电子产生变革性影响。其优异的硬度，高导热性和耐腐蚀性也使这种材料能够在恶劣环境中取代金刚石。氮化硼的研究也将有助于III族氮化物半导体的基础知识。该项目是霍华德和摩根州立大学，两个历史上的黑人学院（HBCU）之间的合作。该项目使摩根和霍华德的学生能够参与具有商业影响的尖端技术。该项目明确地让研究生和本科生参与“动手”研究活动。该项目将资助摩根和霍华德的高级设计项目，学生将把物理电子学的发现转化为真实的系统。该项目将鼓励更多的少数民族参与HBCU的研究生研究项目。为了实现立方氮化硼（c-BN）的全部潜力，期望具有能够实现双极器件以及互补金属氧化物半导体（CMOS）逻辑的n型和p型导电两者。已经证明，浅n型（硅掺杂）和p型（铍掺杂）是可能的，使c-BN成为超宽带隙材料（UWBG）中的独特离群值。在这项工作中，我们研究掺杂和补偿策略，以评估c-BN的前景。 此外，我们测量这种材料的物理特性，如流动性和击穿场作为缺陷形态的函数（必要时更新历史数据）。这项工作涉及小（1毫米）的商业单晶c-BN样品，以及在摩根州生长的大面积薄膜。所有的测量结果都将通过与第一性原理密度泛函理论（DFT）计算进行比较来解释，这些计算提供了一个真正的基于原子物理的理解。这项工作的挑战之一将是生产多型纯材料。为了在化学气相沉积（CVD）期间实现这一点，将不太稳定的六方氮化硼（h-BN）多晶型物蚀刻或溅射掉，从而允许产生立方相。我们将测试3种方法来做到这一点：i）通过H2蚀刻，ii）使用氟基前体和iii）离子束辅助，在单晶HPHT金刚石衬底上。表面制备和后退火将由DFT计算指导。本征点缺陷（例如空位）的补偿和掺杂可能在这种UWBG材料中发挥重要作用，DFT将是理解掺杂起源和电输运的关键工具。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Trap characterization in ultra-wide bandgap Al 0.65 Ga 0.4 N/Al 0.4 Ga 0.6 N MOSHFET's with ZrO 2 gate dielectric using optical response and cathodoluminescence

使用光学响应和阴极发光对具有 ZrO 2 栅极电介质的超宽带隙 Al 0.65 Ga 0.4 N/Al 0.4 Ga 0.6 N MOSHFET 进行陷阱表征

• DOI: 10.1063/1.5125776
• 发表时间: 2019
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Jewel, Mohi Uddin;Alam, Md Didarul;Mollah, Shahab;Hussain, Kamal;Wheeler, Virginia;Eddy, Charles;Gaevski, Mikhail;Simin, Grigory;Chandrashekhar, MVS;Khan, Asif
• 通讯作者: Khan, Asif

Mechanical characterization of boron carbide single crystals

• DOI: 10.1111/jace.18065
• 发表时间: 2021-08
• 期刊: Journal of the American Ceramic Society
• 影响因子: 3.9
• 作者: A. Zare;M. He;Michael Straker;M. Chandrashekhare;M. Spencer;K. Hemker;J. McCauley;K. Ramesh

Photovoltaic and Photoconductive Action Due to PbS Quantum Dots on Graphene/SiC Schottky Diodes from NIR to UV

石墨烯/SiC 肖特基二极管上的 PbS 量子点从近红外到紫外的光伏和光电导作用

• DOI: 10.1021/acsaelm.9b00651
• 发表时间: 2019
• 期刊: ACS Applied Electronic Materials
• 影响因子: 4.7
• 作者: Kelley, Mathew L.;Letton, Joshua;Simin, Grigory;Ahmed, Fiaz;Love-Baker, Cole A.;Greytak, Andrew B.;Chandrashekhar, M. V.
• 通讯作者: Chandrashekhar, M. V.

Ultra-wide bandgap AlGaN metal oxide semiconductor heterostructure field effect transistors with high- k ALD ZrO 2 dielectric

具有高 k ALD ZrO 2 电介质的超宽带隙 AlGaN 金属氧化物半导体异质结构场效应晶体管

• DOI: 10.1088/1361-6641/ab4781
• 发表时间: 2019
• 期刊: Semiconductor Science and Technology
• 影响因子: 1.9
• 作者: Mollah, Shahab;Gaevski, Mikhail;Chandrashekhar, MVS;Hu, Xuhong;Wheeler, Virginia;Hussain, Kamal;Mamun, Abdullah;Floyd, Richard;Ahmad, Iftikhar;Simin, Grigory
• 通讯作者: Simin, Grigory

Doping limitations of cubic boron nitride: Effects of unintentional defects on shallow doping

• DOI: 10.1103/physrevb.105.054101
• 发表时间: 2021-07
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Tamanna Joshi;Pankaj Kumar;Bipul Poudyal;S. Russell;P. Manchanda;P. Dev